Researchers from the American Chemical Society have developed a new solar steam generator that is a huge step towards globally available clean drinking water. Access to clean drinking water is scarce in many areas of the world and researchers believe that we are getting closer to a global water crisis.

Solar steam generation, due to its capability of producing clean water directly by solar energy, is emerging as a promising eco-friendly and energy-efficient technology to address global challenges of water crisis and energy shortage. (Source: American Chemical Society)

The new solar steam water generator’s design was inspired by an origami technique called Miura. This fold is made of interlocking parallelograms that create mountains and valleys to form a 3D structure. The new generator operates with almost 100 percent efficiency when creating clean water, the highest efficiency yet.

Solar steam generators create clean water by converting sun energy into heat, which then evaporates seawater and leaves toxins behind. The steam is collected and condensed to create clean drinking water.

Currently used solar steam generators work, but they are not nearly as effective or efficient. They are made of flat photothermal materials that produce heat from the light. This structure loses energy through heat dissipation easily. The team wanted to search for a better design to stop heat dissipation. That is where the 3D photothermal material came into play.

The new generator is created by depositing light-absorbing nanocarbon composites onto cellulose membranes using the Miura fold. The new structure had a 50 percent higher evaporation rate than the old design. The old design also achieved only 71 percent efficiency, where the new structure has almost 100 percent efficiency. The new structure also captured sunlight and had a better heat flow than the old design.

The paper on this new solar steam generator design to create clean water was published in ACS Applied Materials Interfaces.